Crystal-structure refinement of a Zn-rich kupletskite from Mont Saint-Hilaire, Quebec, with contributions to the geochemistry of zinc in peralkaline environments

2006 ◽  
Vol 70 (5) ◽  
pp. 565-578 ◽  
Author(s):  
P. C. Piilonen ◽  
I. V. Pekov ◽  
M. Back ◽  
T. Steede ◽  
R. A. Gault
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Structure Refinement ◽  
Crystal Structure Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Octahedral Sites ◽  
Mixed Ligands ◽  
High Alkalinity ◽  
Ligand Species

AbstractThe chemistry and crystal structure of a unique Zn-rich kupletskite: (K1.55Na0 .21Rb0.09Sr0.01)Σ1.86(Na0.82Ca0.18)Σ1.00(Mn4.72Zn1.66Na0.41Mg0.12)Σ7.00 (Ti1.85Nb0.11Hf0.03)Σ1.99(Si7.99Al0.12)Σ8.11O26 (OH)4(F0.77OH0.23)Σ1.00, from analkalin e pegmatite at Mont Saint-Hilaire, Quebec, Canada has been determined. Zn-rich kupletskite is triclinic, , a = 5.3765(4), b = 11.8893(11), c = 11.6997(10), α = 113.070(3), β = 94.775(2), γ = 103.089(3), R1 = 0.0570 for 3757 observed reflections with Fo > 4σ(Fo). From the single-crystal X-ray diffraction refinement, it is clear that Zn2+ shows a preference for the smaller, trans M(4) site (69%), yet is distributed amongst all three octahedral sites coordinated by 4 O2− and 2 OH− [M(2) 58% and M(3) 60%]. Of note is the lack of Zn in M(1), the larger and least-distorted of the four crystallographic sites, with an asymmetric anionic arrangement of 5 O2− and 1 OH−. The preference of Zn for octahedral sites coordinated by mixed ligands (O and OH) is characteristic of its behaviour in alkaline systems, in contrast to granitic systems where Zn tends to favour [4]-coordinated, OH− and H2O-free sites with only one ligand species (O, S, Cl, B, I). In alkaline systems, [4]Zn is only present in early sphalerite or in late-stage zeolite-like minerals. The bulk of Zn in alkaline systems is present as discrete [6]Zn phases such as members of the astrophyllite, labuntsovite, milarite and nordite groups, a result of the formation of network-forming complexes inthe low-temperature, low-fS2, high-alkalinity and highly oxidizing systems.

Crystal structure of potassium tetraperoxomolybdate (VI) K2[Mo(O2)4]

2005 ◽  
Vol 20 (3) ◽  
pp. 203-206 ◽  
Author(s):  
M. Grzywa ◽  
M. Różycka ◽  
W. Łasocha
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Rietveld Method ◽  
Structure Refinement ◽  
Crystal Structure Refinement ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters

Potassium tetraperoxomolybdate (VI) K2[Mo(O2)4] was prepared, and its X-ray powder diffraction pattern was recorded at low temperature (258 K). The unit cell parameters were refined to a=10.7891(2) Å, α=64.925(3)°, space group R−3c (167), Z=6. The compound is isostructural with potassium tetraperoxotungstate (VI) K2[W(O2)4] (Stomberg, 1988). The sample of K2[Mo(O2)4] was characterized by analytical investigations, and the results of crystal structure refinement by Rietveld method are presented; final RP and RWP are 9.79% and 12.37%, respectively.

scholarly journals Synthesis, Crystal Structure Refinement, and Electrical Conductivity of Pb(8−x)Na2Smx(VO4)6O(x/2)

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Tatiana M. Savankova ◽  
Lev G. Akselrud ◽  
Lyudmyla I. Ardanova ◽  
Alexey V. Ignatov ◽  
Eugeni I. Get’man ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Solid Solutions ◽  
Structure Refinement ◽  
Crystal Structure Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Solid solutions of Pb(8−x)Na2Smx(VO4)6O(x/2)were studied using X-ray diffraction analysis including Rietveld refinement and scanning electron microscopy and by measuring their electrical conductivity. Crystal structure of the solid solutions was refined and the solubility region0≤x≤0.2was determined for samarium substitution for lead under the scheme2Pb2++□→2Sm3++O2-. The influence of degree of substitution on the electrical conductivity of solid solutions was established.

scholarly journals Synthesis and Rietveld crystal structure refinement of mackinawite, tetragonal FeS

1995 ◽  
Vol 59 (397) ◽  
pp. 677-683 ◽  
Author(s):  
A. R. Lennie ◽  
S. A. T. Redfern ◽  
P. F. Schofield ◽  
D. J. Vaughan
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Structure Refinement ◽  
X Rays ◽  
Crystal Structure Refinement ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Data Set ◽  
X Ray ◽  
Cell Parameters

AbstractMackinawite, tetragonal FeS, has been synthesised by reacting iron with Na2S solutions. A Rietveld structure refinement of X-ray powder diffraction data, recorded using X-rays monochromated from synchrotron radiation with a wavelength of 0.6023 Å, has been performed. The structure has been refined in the tetragonal space group, P4/nmm, and has the following cell parameters: a = 3.6735(4), c = 5.0328(7) Å, V = 67.914(24) Å3. Our refinement shows that the FeS4 tetrahedron in mackinawite is almost perfectly regular, with a much smaller distortion than has been previously reported. An improved X-ray diffraction data set is provided.

scholarly journals Batisite, Na2BaTi2(Si4O12)O2, from Inagli massif, Aldan, Russia: crystal-structure refinement and high-temperature X-ray diffraction study

2017 ◽  
Vol 111 (6) ◽  
pp. 843-851
Author(s):  
Andrey A. Zolotarev ◽  
Elena S. Zhitova ◽  
Faina A. Gabdrakhmanova ◽  
Maria G. Krzhizhanovskaya ◽  
Anatoly A. Zolotarev ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Diffraction Study ◽  
Structure Refinement ◽  
Crystal Structure Refinement ◽  
X Ray Diffraction ◽  
X Ray

Crystal Structure Refinement of M(NCNH)2 (M = Fe, Co) Based on Combined Neutron and X-ray Diffraction Data

2011 ◽  
Vol 637 (9) ◽  
pp. 1089-1091 ◽  
Author(s):  
Xiaojuan Tang ◽  
Andreas Houben ◽  
Xiaohui Liu ◽  
Ludwig Stork ◽  
Richard Dronskowski
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Crystal Structure Refinement ◽  
X Ray Diffraction ◽  
X Ray

Neutronen- und Röntgenbeugungsuntersuchungen an Pulvern und Einkristallen von Strukturverwandten des Berliner Blaus: CsMnIICrIII(CN)6 · D2O , NMe4MnII(Cr0,06,Mn0,94)III(CN)6 · 8 H2O , NMe4MnIICoIII(CN)6 · 8 H20 , Mn3II[MnIII(CN)6]2 · 15 H2O und Cd3[FeIII(CN)6]2 · 15 H2O / Neutron and X-Ray Diffraction Studies on Powders and Single Crystals of Compounds Structurally Related to Prussian Blue: CsMnIICrIII(CN)6 · D2O, NMe4MnII(Cr0,06Mn0,94)III(CN)6 · 8 H2O, NMe4MnIICoIII(CN)6 · 8 H2O, Mn3II[MnIII(CN)6]2 · 15 H2O and Cd3[FeIII(CN)6]2 · 15 H2O

1999 ◽  
Vol 54 (7) ◽  
pp. 870-876 ◽  
Author(s):  
Bernd Ziegler ◽  
Michael Witzel ◽  
Martin Schwarten ◽  
Dietrich Babel
Keyword(s):  
Crystal Structure ◽  
Ambient Temperature ◽  
Single Crystal ◽  
Single Crystals ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Crystal Structure Refinement ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray

The results of a Rietveld refinement of CsMnCr(CN)6 · D2O neutron powder data (a = 1084.3(1) pm, F4̄3m, Z = 4) and of a neutron single crystal structure refinement of tetragonal NMe4MnII(Cr0,06Mn0,94)III(CN)6 · 8 H2O (a = 1065.8(21), c = 1064.6(26) pm, P4/n, Z = 2) at ambient temperature are reported. Single crystal X-ray analyses of the isostructural octahydrate NMe4MnCo(CN)6 · 8 H20 (a = 1062.1 (1), c = 1046.2( 1) pm) and of gel-grown crystals of cubic Mn3II[MnIII(CN)6]2 - 15 H2O (a = 1062.6(3) pm, Fm3̄m, Z = 4/3) and Cd3[Fe(CN)6]2 · 15 H2O (a = 1067.7(3) pm) were performed as well. The latter “Prussian Blues” are highly disordered and intermediate with respect to cyano-bridging between the above three-dimensional cesium and one-dimensional tetramethylammonium compounds.

Crystal structure refinement of the ferroelectric ceramic compound Sm2Bi2Ti3O12

1998 ◽  
Vol 13 (2) ◽  
pp. 113-115 ◽  
Author(s):  
M. E. Villafuerte-Castrejón ◽  
O. Alvarez-Fregoso ◽  
L. E. Sansores ◽  
A. Sànchez-Arjona ◽  
J. Duque ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Structure Refinement ◽  
Ferroelectric Ceramic ◽  
Crystal Structure Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
R Value ◽  
Ceramic Compound

Sm2Bi2Ti3O12 was synthesized by solid state reaction from Sm2O3, Bi2O3, and TiO2 in molar relation 1:1:3. Title compound is isostructural with Bi4Ti3O12. Products of the reaction were analyzed by X-ray diffraction methods. The crystal structure was refinement by the Rietveld Method. Cell parameters are: a=5.368(2), b=5.369(2), and c=32.71(2) Å, space group Fmmm. The final R value was 9.96% (Rw=13.43%).© 1998 International Center for Diffraction Data.

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